The invention is directed to an iodophor solution comprising a mixture of water, 0.5 to 3 weight percent of iodine, 10 to 30 weight percent phosphoric acid, an organic acid and a polymer. The percentages are based on the total weight of the mixture.
Iodophor solutions are aqueous solutions of complex iodine compounds with a content of active iodine of about 0.5 to about 3 weight percent which after dilution with water to the particular active iodine concentration for the use intended are used as disinfectants.
Iodophor solutions based on different formulations are known. They are preferably produced from concentrates having a high active iodine content of about 15 to about 30 weight percent by mixing in a material which dilutes the composition.
Thus, there are known iodophors and iodophor solutions based on polyvinyl pyrrolidone (Beller U.S. Pat. No. 2,706,701). These types of iodophors and iodophor solutions, however, have the disadvantage that only a maximum of 67 percent of their total iodine content is available as active iodine for disinfection purposes, to be sure, according to the work of Robert F. Cournoyer, Polymer Chemistry Edition 12, 603-612 (1964), even then if there is employed to produce the polyvinyl pyrrolidone-iodophors only elementary iodine and there are not used iodine compounds.
There are also known iodophors on a pure tenside basis, Scheib U.S. Pat. No. 2,977,315. In these iodophors the ratio of active iodine to total iodine generally is somewhat more favorable than with polyvinyl pyrrolidone iodophors. However, they have the disadvantage that they have extremely high viscosity and therefore can no longer be pumped. Therefore there must be added to them before their use in industrial systems up to 65% of a relatively expensive, viscosity lowering agent, e.g., hydroxyacetic acid (according to Cantor, German Pat. No. 1,171,112), in order to make the products pumpable again and therewith generally for the first time available industrially.
Besides, these iodophors based on tensides because of their strong tendency to foam are completely unsuited for many industrial processes, for example, in the newer methods of jet purification, high pressure jet purification and spraying purification in breweries, where the development of a foam is undesired and hence, they cannot be used in such places.
Furthermore, there are known iodophor solutions which consist of phosphoric acid, citric acid, sodium polymethacrylate, sodium xylene sulfonate, iodine, hydriodic acid and water (Schmidt U.S. Pat. No. 3,150,096). In these iodophor solutions the relative portions of the various components are of critical significance, e.g., the amount of iodine added must be between 0.5 and 3.0 percent. Therefore, based on their formulation there cannot be produced high iodine containing iodophor concentrates. These iodophor solutions thus cannot be prepared by diluting correspondingly higher iodine containing concentrates but their production is tied each time to its own relatively expensive iodine solubilization process.
A further critical disadvantage of these known iodophor solutions is that for solubilization of iodine there must be added surface active compounds (sodium xylene sulfonate) so that there cannot be produced detergent free iodophor solutions.
It is also known to produce a non-foaming iodophor by mixing while heating to about 50.degree.-120.degree. C for about 0.75-15 hours (1) about 10-30 weight percent of elementry iodine and (2) about 90-70 weight percent of an aqueous solution consisting essentially of (a) about 7-30 weight percent of a polycarboxylic acid or polycarboxylate or mixtures thereof having at least 65 carboxyl or carboxylate groups per molecule, (b) about 0-20 weight percent of an alkali metal iodide, ammonium iodide or mixtures thereof or at least one lower monovalent aliphatic alcohol, (c) about 0-20 weight percent of a non-volatile multibasic mineral acid, a multibasic oxycarboxylic acid or mixtures of such acids which do not substantially reduce elementary iodine and (d) water in amount sufficient that the aqueous solution comprises 100 weight percent (Haschke U.S. Pat. No. 3,984,341). The entire disclosure of Haschke is hereby incorporated by reference and relied upon.